[A functional fitness test battery for pre-frail older adults (so-called "specified elderly individuals")]

In Japan, an exercise program for pre-frail older adults (so-called "specified elderly individuals") (SEIs) has been prescribed under the newly developed long-term care insurance system. Three functional fitness measures (grip strength, one-leg balance with eyes open, and 5-m habitual walk) are used in the system; however, it has yet to be determined if applying these measures to SEIs is appropriate.

The purpose of this study was to develop a new test battery assessing functional fitness for SEIs, and to determine cross-validity and responsiveness of these measures.

One hundred and twenty seven SEIs (76.6 +/- 5.9 yr) and 315 healthy older adults (HOAs) (72.2 +/- 5.8 yr) completed twelve functional fitness tests related to activities of daily living (ADL) and mobility. The SEI was defined by the Japanese Ministry of Health, Labour and Welfare in 2005. The test battery items were selected by logistic regression analysis. A functional fitness score (FFS) equation was developed by principal component analysis. The cross-validity of the FFS equation was then tested using a different set of 28 SEIs (77.5 +/- 6.5 yr) and 143 HOAs (71.5 +/- 4.7 yr). Responsiveness of the FFS was also assessed in 62 SEIs (76.7 +/- 5.9 yr) after a 3-month exercise program.

The following 4 test items were selected for assessment of functional fitness in SEIs: tandem stance, 5-repetition sit-to-stand, alternate step, and timed up and go. Applying principal component analysis to the 4 selected functional fitness items, the first principal component was interpreted as total functional fitness. The following equation was developed to estimate FFS based on the first principal component coefficient of each variable: FFS = 0.031X1-0.106X2-0.192X3-0.096X4 + 1.672, X1 = tandem stance(s), X2 = 5-repetition sit-to-stand (s), X3 = alternate step(s), X4 = timed up and go(s). The cut-off value to distinguish SEIs from HOAs using receiver operating characteristic ROC) curve was 0.065 (sensitivity 82.2%, specificity 81.9%). The cross-validity and responsiveness of the FFS equation was considered acceptable. CONCLUSION This newly developed test battery should be a useful tool for comprehensively evaluating functional fitness in SEIs.